Facebook Political Ads And Accountability: Outside Groups Are Most Negative, Especially When Hiding Donors

TL;DR

This study examines Facebook political ads from 2018, revealing that dark money and disappearing outside groups tend to produce more negative ads, highlighting accountability issues in online political advertising.

Contribution

It provides empirical evidence linking donor transparency and group persistence to ad sentiment, emphasizing accountability's role in political speech tone.

Findings

Dark money ads are significantly more negative.

Disappearing outside groups produce more negative ads.

Accountability influences the tone of political advertising.

Abstract

The emergence of online political advertising has come with little regulation, allowing political advertisers on social media to avoid accountability. We analyze how transparency and accountability deficits caused by dark money and disappearing groups relate to the sentiment of political ads on Facebook. We obtained 430,044 ads with FEC-registered advertisers from Facebook's ad library that ran between August-November 2018. We compare ads run by candidates, parties, and outside groups, which we classify by (1) their donor transparency (dark money or disclosed) and (2) the group's permanence (only FEC-registered in 2018 or persistent across cycles). The most negative advertising came from dark money and disappearing outside groups, which were mostly corporations or 501(c) organizations. However, only dark money was associated with a significant decrease in ad sentiment. These results suggest that accountability for political speech matters for advertising tone, especially in the context of affective polarization on social media.